I agree because I have read several comments in other discussions that in OMAD you can eat whatever you want and even the amount of food doesn’t matter because that will definitely be burned by the fasting that you will undergo. Perhaps we don’t even need to count calories anymore with OMAD unless the admin here would advice us of the contrary.You eat what works best for you. Everyone's body and goals are different. There are no set rules and no one size fits all. Just make sure to follow the 4 ones rule. The Omad diet book is a good book to read if you need help.
https://omaddiet.com/downloads/omaddietguide/
I just go by what I feel. On some days it could be as low as 600 Cal's and on others as high as 1800. I limit my eating to one hour and see how much I feel like eating in that one hour. I thinking mixing it up a little keeps your body guessing and is more akin to the Jason Fung style of fasting.